1. Scope of Invention
This invention relates generally to systems for coating objects by vacuum deposition, and more particularly to a self-aligning and automatically engaging conductive rod or electrode contact system associated with a moveable carriage used to support components and parts during the vacuum deposition process.
2. Prior Art
Vacuum deposition of vaporized metal and plasma-energized protective coatings onto the exterior and interior surfaces of objects such as plastic components for automobile manufacturers which require a high degree of uniformity and finish quality are well known. One major manufacturer of such equipment is F. J. Stokes Corporation.
These prior art vacuum deposition systems typically include a medium to large sized vacuum chamber, a large moveable rack or carriage for holding and supporting a plurality of objects for coating within the chamber, means for conveniently moving the loaded object support carriage into and out of the chamber, an arrangement for producing vaporized metal for depositing a first metallic layer of vaporized metal onto the surface of the objects and a source of vaporized protective liquid such as a monomer which is applied atop the vaporized metal first deposited onto the surfaces of the objects within the vacuum chamber.
The use of a plasma created within the vacuum chamber in the vicinity of the metal coated objects is also typically utilized to energize the vaporized liquid monomer and to accelerate the liquid monomer within the vacuum chamber to facilitate a uniform protective coating applied to the objects.
Applicant is aware of a number of patented prior art systems which are listed below which typically represent the state of the art in vacuum deposition.
______________________________________ 3,086,889 Strong 3,097,113 Welsh 3,117,887 Shepard, et al. 3,518,108 Heiss, Jr., et al. 3,524,426 Ogle, et al. 3,641,973 Shrader 3,713,869 Geffeken, et al. 3,970,820 Mahl 4,173,944 Koppl, et al. 4,338,883 Mahler 4,447,374 Tanaka 4,478,174 Ranger 4,673,588 Bringmann, et al. 4,687,679 Beale 4,863,756 Hartig, et al. 5,053,243 Schuumans, et al. 5,182,000 Atonelli, et al. 5,217,749 Denton, et al. 5,312,529 Atonelli, et al. 5,340,628 Tanisaki, et al. 5,401,541 Hodnett, III 5,538,909 Poliquin, et al. 5,560,963 Tisack ______________________________________
However, for the most part, these prior art references are of limited scope and of a specialty nature, some of which utilize metal vaporizing boats for vacuum deposition of a metallic film. A portion of these references also do not depend upon or require the plasma atmosphere within the vacuum chamber in a fashion similar to that of the present invention.
Further, with respect to those vacuum deposition systems which utilize a moveable carriage or frame which is rollably moved into and out of the vacuum chamber for loading and unloading parts and components for vapor deposition, contact of the metal vaporizing electrodes or rods connected to the carriage is typically made by frictional or surface contact alone. Such a contact arrangement, while economical and simple to use, results in jerking and vibrational movement of these contacts which may reduce vapor deposition consistency. Moreover, because of the high power transfer requirement across these contacts (low voltage, high amperage) substantial power fluctuations may also occur as a result of the vibrational movement between these friction contacts.